1. Technical Field
The present system and method relate generally to network data transmission, and more particularly to efficient distribution of data utilizing an intelligent distribution network.
2. Description of the Background Art
The Internet is a network of virtually connected computers and network-enabled devices currently using Transfer Control Protocol (TCP) and Internet Protocol (IP). TCP/IP is a combination of these two means to deliver data from a host to a client, which involves the breaking down of large data blocks into a plurality of small data packets for transmission by asynchronous transmission electronic devices. Each packet contains packet order information such that when it arrives at a client, the packets can be contiguously reordered even if packets do not arrive in the correct packet order due to intrinsic network behavior. Furthermore, TCP can decide based on intrinsic packet timing criteria whether a packet has been lost or unacceptably delayed, which may result in a subsequent request by the client for a retransmission of the lost or delayed packets. Thus, the greater the number of lost or unacceptably delayed packets, the greater overall decrease to network throughput and increased latency.
When a data packet is transmitted from a host to a client, it passes through various asynchronous transmission devices such as routers, switches, hubs and bridges. Typically, the data packet may incur a latency of approximately 40 ms per transmission device. Because there are numerous paths of varying number of transmission devices that a data packet may travel, a contiguous set of data packets sent from a host may incur considerable timing disruptions making it impossible for the packets to arrive at the client in a contiguous order. Additionally the total delay time for data packet transmission may exceed acceptable ergonomic requirements.
Theoretically, these transmission devices are limited by maximum capacity or bandwidth. For example, a client can presently link to an Internet Service Provider (ISP) through a Public Standard Telephone Network (PSTN) Connection with a modem at a bandwidth capacity typically of fourteen thousand, four hundred bits per second to sixty four thousand bits per second. Alternatively, Broadband Internet Service Providers (BISP) offer larger bandwidth capacity, but essentially function in a similar role of connecting the client to a router at the ISP.
All data to and from clients are combined at the ISP. This combined data can be managed more efficiently as the asynchronous transmission devices are located within the ISP Local Area Network (LAN) that has typical bandwidths of many gigabits per second. Therefore, data that is available within the LAN can be sent to clients of that ISP with maximum network throughput and minimal loss of packets or unacceptable delay. However, when requested information is found outside of the ISP LAN, the Wide Area Network (WAN) is used to connect the ISP or BISP to the host electronic location. Typically bandwidth throughput of the devices in the WAN is less than those of the ISP LAN. Additionally, the cost of use of the WAN is often far higher than that of the LAN.
The Internet was initially perceived and designed to carry text-based e-mail and Hyper Text Transfer Protocol (HTTP) encoded documents. Performance of the Internet using HTTP and text based e-mail is not critically time dependent, thus intrinsic latency of the Internet infrastructure is ergonomically acceptable and utilization of bandwidth is minimal. However, data size and demand has increased through the introduction of concepts such as multimedia content data, which intrinsically contains significantly larger data size. This results in performance problems for real time applications where network timing and sustained data rates are critical. Such applications include streaming media and packet switched telephone networks.
FIG. 1 illustrates the transmission of a data stream from a content server 102 to ISP1 104, ISP2 106 and ISP3 108 and eventually to various end users, via ISP Points Of Presence (POPS) 109, 110, 111, 112, 113, 114, 115, 116, 117. As shown, conventional methods of distribution require a separate transmission for each request from each end user through their respective ISPs 104, 106 and 108. Because the ISP LANs do not contain the requested data, the data must be distributed from the content server 102 through the WAN. However, this method of data transmission presents several problems to both the end users and the ISPs. First, the distribution of streamed data is seriously restricted due to general lack of bandwidth capacity caused by redundant and duplicated transmission to multiple viewers. As shown in FIG. 1, bottlenecks 122 may occur during the transmission from the content server 102 to the ISPs 104, 106 and 108 and during the transmission from the ISPs 104, 106 and 108 to the end users. The bottlenecks 122 reduce viewing quality and access speeds, and increases viewing costs as ISPs pass on bandwidth access or rental costs to the end users. Further, when data packets are lost the end user request for retransmission of that data must be sent back to the content server 102, this retransmission introduces redundant bandwidth utilization effecting all users connected to the server. The addition of bandwidth to overcome this problem is currently very costly to ISPs. Furthermore, because bandwidth constraints are defined by the lowest capacity hop between the content source and the end user, capacity additions to one Internet segment does not necessarily improve overall capacity.
A second problem with the existing transmission scheme is that the Internet does not provide for the most time or cost effective routing of content to end users. In other words, the data travels through more devices (and thus more hops) than would otherwise be optimal. This not only leads to a reduction in viewing quality and access speed, but also reduces the ability of content providers to track and manage the distribution of proprietary content.
The most common method that ISPs employ to manage the dual problems of bandwidth constraint and inefficient routing is to locate dedicated streaming media servers (SMS) within the ISP LAN, to locally store and redistribute content to ISP customers. However, there are a number of problems with this approach. Typically, an ISP can manage the aggregated bandwidth requirement of a plurality of clients streaming a plurality of data packets within the LAN if the data is from a server located within the ISP LAN. Costs to maintain and manage such servers are expensive. Additionally, content providers are often reluctant to provide content to autonomous operators when copyright protection and royalty/licensing fees are at issue. A further disadvantage of having an autonomous local server is that the storage capacity of the server often limits the choice of content available to the ISP clients. Clients often must access stream media through the WAN.
Therefore, there is a need for a more efficient system and method for the distribution content. Furthermore, there is a need for a universal Streaming Media distribution system.